This work was written between December 1989 and June 1990. It was commissioned by the St Magnus Festival and is dedicated to Evelyn Glennie.

Since I had in recent years written a Marimba Concerto (for the American virtuoso William Moersch), I decided in this work to concentrate mostly on unpitched percussion - the many various instruments which cannot produce a definite "note" - rather than the xylophone, vibraphone, marimba etc. This limitation imposed very considerable compositional problems, but the challenge was stimulating and it helped fulfil a request from Miss Glennie, that the concerto should be relatively "portable." Given the enormous number of unpitched instruments that the percussionist has available, I decided in some cases to specify only the type of instrument required rather than the exact instrument. The performer has considerable latitude in other aspects of the performance and is requested to improvise in the course of certain passages.

The concerto is in four movements and lasts about 24 minutes. The third movement is a relatively brief interlude which does in fact use the marimba. This leads directly to the lively finale, which refers back frequently to the previous three movements.